Integrated memory may be used in computer systems for storing data. Integrated memory is usually fabricated in one or more arrays of individual memory cells. The memory cells are configured to retain or store memory in at least two different selectable states. In a binary system, the states are considered as either a “0” or a “1”. In other systems, at least some individual memory cells may be configured to store more than two levels or states of information.
An example memory cell is a programmable metallization cell (PMC). Such may be alternatively referred to as conductive bridging random access memory (CBRAM), nanobridge memory, or electrolyte memory. A PMC may use ion conductive switching material (for instance, a suitable chalcogenide or any of various suitable oxides) and an ion reservoir material proximate the switching material. The ion reservoir material and switching material may be provided between a pair of electrodes. A suitable voltage applied across the electrodes can cause ions to migrate from the ion reservoir material into the switching material to thereby create one or more current-conductive paths through the switching material. An opposite voltage applied across the electrodes essentially reverses the process and thus removes the current-conductive paths. A PMC thus comprises a high resistance state (corresponding to the state lacking a conductive bridge extending through a switching material) and a low resistance state (corresponding to the state having the conductive bridge extending through the switching material), with such states being reversibly interchangeable with one another.
Although there has been effort toward development of PMCs and other memory cells, there remains a need for improved memory cells.